Start
Mar 03, 2011 - 16:00
End
Mar 03, 2011 - 17:00
Venue
Creativity hall (Room 118) Chemical Eng.
Event Type
Speaker
Prof. R. Prabhakar Chemical Engineering Monash University
Title
"Polymer solutions in extensional flows: a bit of stretching helps with concentration"
Abstract: If you stretch out a drop of a viscous polymer solution between your fingers how long would the filament take to break up? The answer to this simple question has some important applications. Polymeric additives are used in inks agricultural sprays etc. to control undesirable splattering of drops and jets into tiny droplets. Individual polymer molecules stretch during flow to confer a spring-like elasticity to slender filaments of polymer solutions. However the dynamics of such filaments are not well understood. A curious observation is that solutions that are supposed to be dilute behave as if they are quite concentrated when stretched into filaments. This self-concentrating behaviour further enables thin filaments to resist the crushing grip of surface-tension for much longer than expected. In this talk I will try to show why this is so.